The new laser tube was delivered and I was able to install it this weekend so we are good to go for the laser cutter class tonight (8/20).

I was also able to expand the work area from 12x8 to 12x9 inches. When fixing the laser cutter I was able to get into the internals enough to see how everything works and am confident I will be able to significantly expand the work area by building and external X-Y table as a work area. I am think that it would be something like 4 feet by 2 feet. I already have acquired some of the new parts for the expansion like 2 meters of case hardened steel rod for bearings and 50' of stepper motor timing belt material (LL2MR09). However with everything else that is going on, I don't think that I will be able to complete that project until after sometime in September.

I had an interesting discussion with a guy at the robotics group about a system he had worked on that allowed a laser cutter of our power range to cut metal by using a capacitive sensor to focus the beam very tightly, melting a small amount of the metal and using pressurized oxygen to blow the material out. I wonder if we could build something like that.

Automated Capacitive Height Control

I switched out the ventilation fan with the twin turbine blower, and have had unsatisfactory results. We need more suction to blow the vapors from the cutting process out of the machine to the outside so that it doesn't stink up the downstairs room so much. At this point I'm thinking of trying to hook up a vacuum to it.

Yesterday (8/22) morning I went in to do some stuff on the laser cutter and I found that the MoshiDraw 2012 and CorelDraw programs had been uninstalled from the computer by someone. I reinstalled the software. Then last night I went in again for the open house and coming in I could smell that plastic smell all the way upstairs. Someone must have been running a major project during the day. I have found a wet vac on Craigslist which I will get Friday after work to use for suction to better ventilate the machine, putting the wet vac outside the window.

Anyway, when I started the laser cutter up last night, I found that someone had replaced the water in the water coolant container with tap water instead of distilled water. My understanding from others is that this was done because the water had gotten hot. In replacing the water they had dislodged the tube from the water pump and it wasn't pumping water. I found the end of the tube, which should have been attached to the output of the pump, laying next to the water container in a puddle. The heating of the tube appeared to have damaged the electrical connections on the tube and we performed some repairs last night to try and fix that. Fortunately, it doesn't look like the glass of the tube was damaged like last time. Unfortunately, the tube appears to be operating at half the power it had when I installed it last weekend.

Also, I have gotten complaints from people about missing materials, in particular acrylic. People bring in acrylic but then next time they come in some of it is gone. For myself, all the thin acrylic I had brought in appears to be gone, and half of the thick acrylic. There are scraps there for people to use and the cardboard and wood is fair play. The Hack Factory does not supply the acrylic or otherwise pay for the laser cutter, materials, upgrades, or repairs. The Hack Factory collects money from the classes and it provides the space and electricity. Also, the monitor we are using is from a donation to the Hack Factory.

I'll speak up with regard to missing raw materials only: It is good practice to label your raw materials clearly. If you bought acrylic or plywood or lagbolts and left them lying about without your name on it, you are partly at fault for it having been used by someone else. It is also good practice to examine any apparently available raw material for names or other marking, and if there is ANY doubt, don't use it.

Working with the laser today and it seems like the Y axis stepper motor is going - gone. I tried to clean as much with the shop vac as I could to remove any chunky bits that might have fallen in the belt but still get a whining grinding noise just on the Y axis. Didn't want to tear into it without checking first.

Also found that some file settings in jpeg files will cause it to error out. These can be corrected by converting to B/W bmp files.

Shiftyhack,Thanks for the heads up. I was finally able to go in today (10/8) and look at the laser cutter to see what was going on. I rigged the Y axis stepper motor that was having problems up to the he X axis line and it moved the Y axis stepper motor just fine, indicating that the problem wasn't with the stepper motors. I was able to track the problem down to the Moshi controller board (where the USB cable plugs into) by swapping out the stepper motor lines. I was worried that it was time to purchase the LAEP project's contemplated new laser controller board early, which would be problematic because I just sank most of my money into that corrugated steel building.

I noticed a heat sink was loose and then swapped out some of the TEA3718S chips and discovered that one of the TEA3718S stepper motor driver chips was not working. I was able to find a source on eBay and ordered a new TEA3718S chip. I'm not sure how long it will take to be delivered from Arizona.

Bad Stepper Motor Controller Chip

TEA3718S.JPG (28.3 KiB) Viewed 5302 times

Also, thanks for the posting about the jpeg issue. That explains an issue Chas was having at the October laser cutter class. The next laser cutter class will probably be in November.

Shiftyhack wrote:Thanks so much. I look forward to testing out my new images and hopefully get reliable results. Just wondering,, are these controller chips heating up on the board. Would a mini heat sink help?

The chips have heat sinks, but I think one of the heat sinks came loose before as it wasn't tight when I discovered the failed chip. I tightened the heat sinks down good when I installed the new stepper motor chip.